Method for preparing paraxylene and propylene

A technology for p-xylene and propylene, which is applied in the field of high-selectivity preparation of p-xylene and propylene, can solve problems affecting economy, large investment and energy consumption, and achieve the effect of improving economy and avoiding high costs

Active Publication Date: 2015-06-17
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that to obtain high-purity ethylene products, cryogenic separation technology must be used, and the investment and energy consumption are large, which directly affects the economy of the process.

Method used

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  • Method for preparing paraxylene and propylene
  • Method for preparing paraxylene and propylene
  • Method for preparing paraxylene and propylene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Embodiment 1 (catalyst 1 preparation)

[0045] 500g ZSM-5 zeolite molecular sieve raw powder (SiO 2 / Al 2 o 3 =68) (Catalyst Factory of Fushun Petrochemical Company) Roasted at 550°C to remove template agent, exchanged 4 times with 0.5 molar equivalent ammonium nitrate solution in 80°C water bath, dried solid samples in air at 120°C Calcined in air for 4 hours to obtain HZSM-5 zeolite molecular sieve.

[0046] Modification of HZSM-5 zeolite molecular sieve by hydrothermal treatment: Take 200g of HZSM-5 molecular sieve and place it in a quartz reactor, heat it up to 650°C and then feed water with a water flow rate of 5ml / min, and treat it at a constant temperature for 4 hours to obtain a hydrothermal modification. Sexual HZSM-5 zeolite molecular sieve. Surface modification of hydrothermally modified HZSM-5 zeolite molecular sieves was carried out using siloxane reagent tetraethyl silicate. The steps are: immerse the hydrothermally modified HZSM-5 zeolite molecular s...

Embodiment 2

[0047] Embodiment 2 (catalyst II preparation)

[0048] (1) 500g ZSM-5 zeolite molecular sieve raw powder (SiO 2 / Al 2 o 3 =38) (Nankai University Catalyst Factory) roasted at 550°C to remove the template agent, exchanged 4 times with 0.5 molar equivalent ammonium nitrate solution in a water bath at 80°C, dried the solid sample in air at 120°C after exchange, and dried it at 550°C Calcined for 4 hours to obtain HZSM-5 zeolite molecular sieve.

[0049] (2) Take 200g of the HZSM-5 zeolite molecular sieve prepared in step (1), and use 8% mass concentration of zinc nitrate [Zn(NO 3 ) 2 ·6H 2 O] soaked in the solution at room temperature for 4 hours, poured out the upper liquid, dried the solid sample in air at 120°C, and roasted in air at 550°C for 6 hours to obtain zinc-modified Zn-HZSM-5 zeolite molecular sieve. Elemental analysis shows that the Zn content is 2.45wt%.

[0050] (3) Use orthoethyl silicate (TEOS) to impregnate the Zn-HZSM-5 zeolite molecular sieve obtained i...

Embodiment 3

[0058] Example 3 ( figure 2 reaction system shown)

[0059] The TMPC-01 prepared in Example 1 and the TMPC-02 catalyst prepared in Example 2 were pressed into tablets respectively and crushed and sieved into 40-60 purpose catalyst samples, and each 10 grams of catalyst was loaded into the two sides of the fixed bed reactor. a reaction zone. The first reaction zone carries out the conversion reaction of toluene and methanol, and the second reaction zone carries out the ethylene aromatization reaction. 2 - The composition of components prepares ethylene-rich raw materials and enters the second reaction zone for aromatization.

[0060] Reaction conditions: The mass space velocity of toluene in the first reaction zone is 2h -1 , the reaction temperature is 480°C; the reaction temperature in the second reaction zone is 450°C. Gas chromatography was used to analyze the composition of the mixed product in the reaction zone online, and the distribution of hydrocarbon products af...

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Abstract

The invention provides a method for preparing paraxylene and propylene. According to the method, two reaction processes including an alkylation reaction between methylbenzene and methanol or/and dimethyl ether and an aromatization reaction of ethylene are coupled. An ethylene-rich C2<-> component in by-products of the alkylation reaction between methylbenzene and methanol or/and dimethyl ether for preparation of paraxylene is recycled to undergo a shape-selective aromatization reaction so as to highly selectively prepare paraxylene and propylene.

Description

technical field [0001] The invention belongs to the field of chemistry and chemical engineering, and particularly provides a method for preparing p-xylene and propylene with high selectivity. Background technique [0002] Both p-xylene (PX) and propylene are important basic chemical raw materials. At present, p-xylene is mainly obtained through aromatics complex. Since the content of p-xylene in the three isomers is controlled by thermodynamics, p-xylene only accounts for about 23% of the xylene isomers, especially the difference in boiling points between the three isomers of xylene is very small, and the usual Distillation technology cannot obtain high-purity p-xylene, but an expensive adsorption separation process must be used. Therefore, in the entire PX production process, the amount of material circulation is large, the equipment is huge, and the operating cost is high. Propylene is mainly derived from petroleum refineries and naphtha steam cracking to produce ethyle...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C15/08C07C11/06C07C2/88C07C2/42C07C1/20B01J31/26
CPCY02P20/52Y02P30/20Y02P30/40
Inventor 许磊王莹利刘中民张新志
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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